How does a flashlight illustrate the Law of Conservation of Energy? (1 point)
O Potential energy in the battery will be converted to kinetic energy.
Potential chemical energy in the battery is converted to electrical energy, which is converted to light energy and heat energy.
All of the electrical energy leaving the battery will travel through the circuit and return to the battery.
O It is an electric circuit through which electrical energy flows.
Potential chemical energy in the battery is converted to electrical energy, which is then converted into light energy and thermal energy. This conversion of energy illustrates the Law of Conservation of Energy, which states that energy cannot be created or destroyed, only transformed from one form to another. In the case of a flashlight, the chemical energy in the battery is transformed into various forms of energy, but the total amount of energy remains constant.
Which is an example of a load in an electric circuit?(1 point)
Responses
9-volt battery
9-volt battery
on-off lever
on-off lever
speaker
speaker
wiring
Speaker is an example of a load in an electric circuit.
Which of the following best describes an electric circuit that powers a load?(1 point)
Responses
Electric current flows from an energy source through a conductor and back to the energy source.
Electric current flows from an energy source through a conductor and back to the energy source.
Electric current flows from an energy source directly to the load.
Electric current flows from an energy source directly to the load.
Electric current flows from an energy source through a conductor to a load and back to the energy source.
Electric current flows from an energy source through a conductor to a load and back to the energy source.
Electric current is generated in a conductor and flows through wires to a load.
Electric current flows from an energy source through a conductor to a load and back to the energy source.
Hal makes an electromagnet with a 9-volt battery, wire, and a steel rod. What is the function of electric current in his electromagnet? (1 point)
Responses
Electric current determines the strength of the magnet.
Electric current determines the strength of the magnet.
Electric current attracts or repels charged objects.
Electric current attracts or repels charged objects.
Electric current powers the electromagnet.
Electric current powers the electromagnet.
Electric current creates a magnetic field that charges the rod.
Electric current creates a magnetic field that charges the rod in Hal's electromagnet.
What is the function of the core of an electromagnet?(1 point)
Responses
The core provides the magnet with electric energy.
The core provides the magnet with electric energy.
The core provides the conductor through which electric current flows.
The core provides the conductor through which electric current flows.
The core is the part that becomes magnetized.
The core is the part that becomes magnetized.
The core is the flow of electrons that charges the magnet.
The core is the part that becomes magnetized in an electromagnet.
In 1–2 sentences, describe a setup of pith balls that have negative charges and are hanging from the same point.(2 points)
When pith balls have negative charges and are hanging from the same point, the balls will repel each other and move away to form a V-shape because like charges repel.
In 1–2 sentences, describe the factors that affect the current (amperage) in an electric circuit.
The current (amperage) in an electric circuit varies depending on the voltage, resistance, and voltage source of the circuit.
A team of students builds an electrical circuit with a battery and a fan. In 1–2 sentences, describe how energy is changed from one form to another in their electric circuit.
In their electric circuit, energy is transformed from the chemical potential energy of the battery into electrical energy, which powers the fan, causing mechanical energy to be generated to rotate its blades and air movement.
In 1–2 sentences, explain how to make an electromagnet.
To make an electromagnet, you will need an iron or steel core, wire, and a power source such as a battery. The wire should be wrapped around the iron core and connected to the battery to create an electrical current that magnetizes the iron core.
In 1–2 sentences, explain how electromagnets move a maglev train.
An electromagnet-based levitation system uses the repulsion between like poles of magnetic fields to push the train up and keep it hovering above the tracks, while the magnetic field created by a current flowing through a coil on the train produces a propulsion force that moves it along the tracks.
A group of students sets up an electric circuit with wires, a battery, and a light bulb. Why is their circuit called a direct circuit?
Responses
The circuit is complete, so electrons can flow freely.
The circuit is complete, so electrons can flow freely.
The light bulb is directly connected to the battery.
The light bulb is directly connected to the battery.
The electrons flow back and forth through the circuit.
The electrons flow back and forth through the circuit.
The flow of electrons travels in one direction.
The flow of electrons travels in one direction in a direct circuit.
Sally puts on wool socks and rubs her feet on a nylon carpet. How does static electricity build up in Sally?
Responses
Electrons from the wool socks move into the carpet, giving Sally and her socks a positive charge.
Electrons from the wool socks move into the carpet, giving Sally and her socks a positive charge.
Electrons from the carpet move into the wool socks, giving Sally and her socks a positive charge.
Electrons from the carpet move into the wool socks, giving Sally and her socks a positive charge.
When electrons from the wool socks move into the carpet, Sally and her socks gain a negative charge.
When electrons from the wool socks move into the carpet, Sally and her socks gain a negative charge.
The friction causes electrons from the wool socks to move to Sally, giving Sally a negative charge.
When electrons from the wool socks move into the carpet, Sally and her socks gain a positive charge.
How do the frequencies and the speeds of yellow light and blue light compare?(1 point)
Responses
The frequency of blue light is greater than that of yellow light, while the speed of yellow light is faster than that of blue light.
The frequency of blue light is greater than that of yellow light, while the speed of yellow light is faster than that of blue light.
The frequency of yellow light is greater than that of blue light, while the speeds of both colors of light are the same.
The frequency of yellow light is greater than that of blue light, while the speeds of both colors of light are the same.
The frequency of yellow light is greater than that of blue light, while the speed of blue light is faster than that of yellow light.
The frequency of yellow light is greater than that of blue light, while the speed of blue light is faster than that of yellow light.
The frequency of blue light is greater than that of yellow light, while the speeds of both colors of light are the same
The frequency of blue light is greater than that of yellow light, while the speeds of both colors of light are the same.
A stationary source produces a sound wave at a frequency of 100 Hz. The wave travels at 1125 feet per second. A car is moving toward the sound source at a speed of 200 feet per second.
What is the wavelength of the stationary sound source and the wavelength that a person in the car perceives?
(1 point)
Responses
wavelength of the stationary source: 9.25 ft; perceived wavelength: 11.25 ft
wavelength of the stationary source: 9.25 ft; perceived wavelength: 11.25 ft
wavelength of the stationary source: 11.25 ft; perceived wavelength: 9.25 ft
wavelength of the stationary source: 11.25 ft; perceived wavelength: 9.25 ft
wavelength of the stationary source: 13.25 ft; perceived wavelength: 11.25 ft
wavelength of the stationary source: 13.25 ft; perceived wavelength: 11.25 ft
wavelength of the stationary source: 11.25 ft; perceived wavelength: 13.25 ft
The wavelength of the stationary source is 11.25 ft and the perceived wavelength by the person in the car is 9.25 ft.
Which phrase correctly defines the amplitude of a wave?(1 point)
Responses
the vertical distance from the trough of a wave to the crest
the vertical distance from the trough of a wave to the crest
the horizontal distance from the trough of one wave to the trough of the next wave
the horizontal distance from the trough of one wave to the trough of the next wave
the horizontal distance from the crest of one wave to the crest of the next wave
the horizontal distance from the crest of one wave to the crest of the next wave
the vertical distance from the crest or trough of a wave to the equilibrium